Add missing dependency to the API doc building workflow

Author: popescu-v

.github/workflows/api-docs.yml

@@ -67,6 +67,9 @@ jobs:
         run: echo PATH="$PATH:/github/home/.local/bin" >> "$GITHUB_ENV"
       - name: Install doc build requirements
         run: |
+          # Install tomli so that pyproject.toml can be parsed
+          pip3 install tomli
+
           # Install package itself to install the samples datasets
           pip3 install .
           kh-download-datasets --force-overwrite